Crown-root morphology of adjacent lateral incisors in patients with palatally impacted maxillary canines:A cone-beam CT study / 医学研究生学报

ABSTRACT

Objective Maxillary canine palatal impaction is a common deformity in stomatology and its etiology remains dis-putable.The aim of this study is to investigate the crown-root morphology of the adjacent lateral incisors in patients with palatally impacted maxillary canines using cone-beam computed tomography ( CBCT) in order to explore its etiology. Methods Using CBCT scanning, we examined 94 maxillary canines in 84 patients, including 27 palatally impacted maxillary canines in 24 patients ( the experi- mental group) , 37 buccally impacted maxillary canines in 30 age-and sex-matched subjects ( control group A) , and 30 normal maxil-lary canines in 30 age-and sex-matched subjects ( control group B) .We selected some necessary reference planes, measured the ori-entation and position of the chosen canines, and studied the morphology of the adjacent lateral incisors by CS 3D imaging, followed by statistical analysis of 17 of the linear variables obtained. Results Compared with control group A, the experimental group showed significantly shorter tooth length ([22.930 ±1.849]mm vs [21.240 ±1.651]mm, P<0.05), crown length ([9.270 ±0.559]mm vs [8.150 ±0.889] mm, P<0.05), and mesiodistal width at 4 mm to the cementoenamel junction (CEJ) ([7.260 ±0.579]mm vs [5.900 ±0.581] mm, P<0.05) as well as shorter buccolingual width at the CEJ level, mesiodistal width at 4 mm to the CEJ, buc-colingual width at 4 mm apical to the CEJ, distance from the canine cusp to the coronal and occlusal planes, and coronal angulation of the canine (all P<0.05).There was a negative correlation between maxillary canine palatal impaction and age (P<0.05). Conclusion One of the main causes of maxillary canine palatal impaction is that the adjacent lateral incisor is too small to provide suf-ficient guidance to the canine.The severity of maxillary canine palatal impaction increases with the age of the patient.